After all, why America is jealous of India's UPI? Actually, the US financial market is not controlled by the government of the US, but by the banks and financial institutions of the US, which includes big corporations like Visa and MasterCard.
Now, if people start using free services like UPI in America, then Visa and MasterCard, which gets 3-4% service charge, will be finished. And because the US economy runs because of these big corporations and banks, that's why the government of the US can't take any strict steps against these institutions.
That's why the US can never control the UPI.